Solera

Lore & Background

The term solera means 'on the ground' in Spanish, referring to the lowest level of stacked barrels where the oldest mixtures reside. The process involves a succession of containers called scales, criaderas, or clases, filled over equal aging intervals. At each interval, the oldest scale is partially tapped for bottling, then refilled from the next oldest, and so on down to the youngest, which receives new product. No container is ever completely drained, so traces of the very first product may remain even after 50 or more cycles. The first written mention of the solera may be in the 1849 inventory of the house of Garvey, though the term was probably in use earlier. In Andalusia, Spain, regulations require careful labeling and record-keeping, usually via computer, to determine the average age of each container.

Reader's Guide

The solera process has been adopted for a wide range of products including Sherry, Madeira, Lillet, Marsala, Mavrodafni, Muscat, Muscadelle wines, balsamic vinegar, Commandaria, some vins doux naturels, sherry vinegars, Brandy de Jerez, beer, rums, and whiskies. In Sicily, the similar system for Marsala is called in perpetuum. In Sweden, the process has been used since the 17th century to produce sour ales known as hundraårig öl. In Okinawa, Japan, the traditional system for awamori is called shitsugi. The solera method is also employed by craft breweries in the United States for beer. In rum production, the term 'solera' is commonly used, though according to one rum expert, no rum has been seen to be aged in a true solera method, with most using dynamic blending instead. The age of the first bottling equals the number of containers times the aging interval; as the solera matures, the average age asymptotically approaches a value determined by the number of scales and the fraction transferred.

Did You Know?

• The solera process allows traces of the very first product to remain even after 50 or more cycles.
• In a Spanish sherry solera, the vintner may transfer about a third of each barrel a year.
• Glenfiddich uses a vatting process similar to solera for its 15-year-old single malt Scotch whisky.